Since the invention of the printing press, printed images have become a common way to communicate information. Printed images can include text, as well as other types of image content such as photographic images and graphical image elements (e.g., pie charts, logos and computer generated artwork).
While printed images are effective to communicate information to sighted persons, there is a significant minority of the human population who suffer from visual impairment, including blindness. Printed images have little or no value for this population segment.
A variety of methods have been developed for communicating information to visually impaired individuals. The Braille system is a method that is widely used by people who are visually-impaired to enable them to read and write. Braille was devised in 1825 by Louis Braille, and involves forming tactile characters using patterns of raised dots. Each Braille character, or cell, is made up of six dot positions, arranged in a rectangle containing two columns of three dots each. A dot may be raised at any of the six positions to form sixty-four possible arrangements (including the arrangement in which no dots are raised). Conventionally, Braille characters are “printed” using devices that emboss the desired dot patterns into a receiver such as paper.
In recent years, various systems have been developed for forming tactile patterns, including Braille characters, using electrographic printing technology. For example, commonly-assigned, U.S. Patent Application Publication 2008/0159786 to Tombs et al., entitled “Selective printing of raised information by electrography,” and commonly-assigned U.S. Pat. No. 8,064,788 to Zaretsky et al., entitled “Selective printing of raised information using electrography,” describe methods for printing raised information with a tactile feel using toner particles having a substantially larger size than standard size marking particles that are used to form printed images.
Commonly-assigned U.S. Patent Application Publication 2011/0200360 to Tyagi et al., entitled “System to print raised printing using small toner particles,” and commonly-assigned U.S. Patent Application Publication 2011/0200933 to Tyagi et al., entitled “Raised printing using small toner particles,” disclose methods to print raised letters using small toner particles that involve using multiple layers of toner.
Commonly-assigned U.S. Patent Application Publication 2011/0200932 to Tyagi et al., entitled “Raised letter printing using large yellow toner particles,” discloses a method to produce prints with raised letters by forming multi-color toner images and fusing the print one or more times.
A variety of other methods are also known in the art for forming tactile image content. For example, commonly-assigned U.S. Pat. No. 5,125,996 to Campbell et al., entitled “Three dimensional imaging paper,” discloses an imaging paper having dispersed throughout hollow expanding synthetic thermoplastic polymeric microspheres. Tactile information can be provided by using a scanning laser beam (or some other thermal source) to cause discrete areas of the paper to expand.
Zychem Ltd of Middlewich, Cheshire, UK have developed a product known as Zytex2 Swell Paper onto which images can be printed and made into tactile diagrams. This product can be used to form, Braille or other forms of tactile patterns. An image can be printed onto the paper, and when the paper is heated using one of our Zyfuse heating machines, the black parts of the image swell up to become tactile. This approach has the limitation that the tactile features are constrained to have a direct correspondence to the black image regions.
U.S. Pat. No. 4,972,501 to Horyu, entitled “Image processing apparatus,” discloses an apparatus to enable a blind person to read characters written on a paper. The apparatus includes a photo-sensor which is used to scan the printed text. The scanned image pattern is converted to mechanical vibrations using piezoelectric elements or LEDs.
Commonly-assigned U.S. Pat. No. 6,755,350 to Rochford et al., entitled “Sensual label,” and commonly-assigned U.S. Pat. No. 7,014,910 to Rochford et al., entitled “Sensual label,” discloses a pressure sensitive adhesive label including at least one tactile or olfactory feature. Tactile features are provided by a textured overcoat later. The form of the tactile and olfactory features can be chosen to be related to visual content included on the label.
U.S. Pat. No. 7,290,951 to Tanaka et al., issued Sep. 7, 2006, entitled “Braille layout creation method, Braille layout creation system, program, and recording medium,” discloses a Braille layout creation method where Braille characters are embossed into an object frame, in association with corresponding printed text characters.
U.S. Patent Application Publication 2002/0003469 to Gupta, entitled “Internet browser facility and method for the visually impaired,” discloses a method for facilitating internet browsing for the visually impaired. The method involves using a matrix of movable tactile elements to display a representation of a file containing hypertext links. Text is translated to Braille and graphics images are converted to a dot matrix representation, with selective simplification.
There remains a need for a method to effectively convey information pertaining to photographs and graphics, to both sighted persons and visually impaired persons.